Find the Town Judge

找到一个人, 被所有人trust, 但是不trust任何人. 依照题意写就行了.

class Solution {
    public int findJudge(int N, int[][] trust) {
        int[] trusted = new int[1001]; // count of being trusted
        boolean[] trustTo = new boolean[1001]; // true = trust to someone
        for(int i = 0 ; i < trust.length; i++) {
            trusted[trust[i][1]]++;
            trustTo[trust[i][0]] = true;
        }
        for(int i = 1 ; i < 1001; i++) { 
            if(trusted[i] == N-1 && !trustTo[i]) // N-1 = being trusted by all others expected self. trustTo = false  -> trust noone
                return i;
        }
        return -1;
    }
}